The Great Masquerader Complete Heart Block (CHB) With Crusader Hyperkalemia in an Elderly: The Lessons to Reckon

Cardiac impulse conduction involves the passage of impulse from sinoatrial (SA) node to atrioventricular (AV) node, and then through Bundle of His, Bundle branches, Purkinje fibers, and finally Ventricles. Potassium, an extracellular ion plays an important role in the electrophysiologic function of the myocardium. A high serum potassium level impairs the impulse conduction in purkinje fibers and ventricles more than that in the AV node. Therefore, although complete AV block (Complete Heart Block -CHB) can occur, it is a rare initial presentation. Here we present an elderly lady of 78 years with Diabetes mellitus and Hypertension comorbidities presenting with giddiness of 2 days duration and diagnosed to have CHB with hyperkalemia, which responded remarkably to conservative treatment. However post treatment electrocardiogram (ECG) depicted Right bundle branch block (RBBB) pattern and the puzzle for such finding was resolved. The present case thus offers a clear clinical message impacting the medical practice.